(1)Systems architecture design (External design)
In a systems architecture design, components that are visible to the user
(system user department) are designed.
The functions required for the system are identified by considering how
operations will change if the system is developed, and human interfaces
such as input/output screens and forms/slips are designed. System architecture design is also referred to as an “outline design” as it outlines the
type of system that will be used.
In system architecture design, “human interface design” such as input/
output screens and forms/slips, as well as “data design” and “code design” are implemented.
Reference
Human interface design
Refer to “Chapter 9-1-1 Human interface technology.”
Reference
Data normalization
Refer to “Chapter 9-3-2 Database design.”
●Human interface design
“Human interfaces” are points of contact between people and computers.
They are also referred to as “user interfaces.” In human interface design,
the input/output screens of the system and print images such as forms/slips
are designed.
●Data design
In data design, table data is designed in order to utilize relational databases. By extracting all data items used in operations and normalizing the
data, redundant data is removed.
●Code design
In a system, various codes such as product numbers and customer numbers
are handled. As these codes require regularity, the rules and items to be encoded are determined by the code design.
(2)Software architecture design (Internal design)
In software architecture design, an internal system is designed, which considers “how to implement” the necessary functions of the system. In other
words, it is designed from the perspective of using programming to implement the functions determined in the system architecture design.
The user (system user department) does not participate in software architecture design since it is a design of the system’s internal functions.
Reference
SQL
Refer to “Chapter 9-3-3 Data manipulation.”
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(3)Software detailed design (Program design)
The internal structure of programs is designed based on the software architecture design.
In software detailed design, function details in programs are defined, and
detailed processing units of the program structure such as database access
methods (SQL statements) are designed.
The user (system user department) does not participate in software detailed
design since it is design of the system’s internal functions.